From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 057953850425; Mon, 27 Jul 2020 06:41:27 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 057953850425 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1595832088; bh=5pz87luxm5vc+kDu7+OtMhCZkjgrBXve1o2EygcTocQ=; h=From:To:Subject:Date:In-Reply-To:References:From; b=JvN5OZrhKEHhsB971f7EMOdgwoaro8kH1+YkAFNxmz5LtYmnlpzmBGONDYzhXA6ss xaI7df3wQSVlzYt1UG/hBviD5LDsyKAUQf6In3qb5k93G5DD2Hy68Kifj2cnWSQysQ qSnvzKwk5hvBxUNpu31KC5NS7aF9XHVXniZ+QSOw= From: "marxin at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/96326] [10/11 Regression] Incorrect loop optimization at -O3 since r10-4803-g8489e1f45b50600c Date: Mon, 27 Jul 2020 06:41:27 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Version: 10.2.0 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: marxin at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc cf_reconfirmed_on short_desc bug_status everconfirmed Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Jul 2020 06:41:28 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D96326 Martin Li=C5=A1ka changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |marxin at gcc dot gnu.org, | |rguenth at gcc dot gnu.org, | |rsandifo at gcc dot gnu.org Last reconfirmed| |2020-07-27 Summary|Incorrect loop optimization |[10/11 Regression] |at -O3 |Incorrect loop optimization | |at -O3 since | |r10-4803-g8489e1f45b50600c Status|UNCONFIRMED |NEW Ever confirmed|0 |1 --- Comment #3 from Martin Li=C5=A1ka --- Started with r10-4803-g8489e1f45b50600c. I see: $ gcc pr96326.c -fsanitize=3Dundefined && ./a.out=20 pr96326.c:11:23: runtime error: store to misaligned address 0x7fffffffe263 = for type 'long unsigned int', which requires 8 byte alignment 0x7fffffffe263: note: pointer points here 00 61 62 63 00 00 00 00 00 e0 69 61 f7 ff 7f 00 00 29 00 00 00 00 00 00= 00=20 88 ff ff ff ff ff ff ^=20 pr96326.c:16:23: runtime error: store to misaligned address 0x7fffffffe26c = for type 'long unsigned int', which requires 8 byte alignment 0x7fffffffe26c: note: pointer points here 63 61 62 63 00 00 00 00 29 00 00 00 00 00 00 00 88 ff ff ff ff ff ff ff= 40 6a 61 f7 ff 7f 00 00 ^=20 68 and ASAN returns a different value: $ gcc pr96326.c -fsanitize=3Daddress && ./a.out=20 70 Same for clang: $ clang pr96326.c -fsanitize=3Daddress && ./a.out=20 70 So I bet the test-case must be invalid?=